Hi Greg

 

Theroplastics are more difficult to bond to but not impossible.  Remember that snow ski bottoms have the Ptex (polyetylene) bonded to the glass or carbon bottoms. There are a couple of ways to bond it.  One is to clean with solvent, abrade and prime with Dow Corning A-4094 or GE SS-4101.  Then bond using a bonding adhesive like the Hysols.

 

Another way is to treat the surface with plasma or flame treatment.  This means taking a flame spreader and a propane torch and lightly running it over the surface with the flame.  There really isn't much to it.  So as before, clean the surface very well and I rough the surface up with some rough sandpaper like 36 grit if it's thick enough, then clean again.  Next, take your torch and lightly (as in LIGHTLY) pass the flame over the surface.  If you watch the surface reflected off of a light, you can actually see the change in the surface which signals the breaking of the surface molecules and thus raising the surface energy.  If you melt the surface, you went too far.  You really only want the hot plasma in the flame to "attack" the surface molecules of the plastic.  There is one other treatment using concentrated sulfuric acid but that doesn't sound like much fun and I've never used it.  I have however used the plasma and it is very easy.  I tried using some ABS tubing edge bonded into a sheet as a core on a project requiring pre-shaping.  It bonded extremely well.

 

Dan